How do I put Lightroom.4.2 in "Open With"?

Question

How do I enter Lightroom 4.2 in "Openwith"?

Answer 1

~cynthiak~ wrote:
Since upgrading to 4.2, Lightroom is not on the list and when I click on Other Programs and browse the lightroom.exe, nothing happens. I'm still at the Open With window.
When you click on Other Programs, do you see Lightroom in the list?
Or do you have to click Browse and point out the location of lightroom.exe?
If the latter, is Lightroom then added to other Programs, or is it still missing?
The problem can be that Lightroom is not correctly registered by Windows. I don't know the specifics, but apparently you can't add a program to Open With in Windows 7 if it doesn't have a certain key in the Windows Registry. In older versions of Windows, you just needed an .exe. No registry keys were required.
In one of the Lightroom 3.x versions I was also hit by this and had to add the key manually to the Windows registry.
To check if the key is missing, try this:
Run regedit.exe
Go to HKEY_CLASSES_ROOT\Applications\
There should be a key called lightroom.exe
This key has the subkeys shell -> open -> command
Under command there should be one entry like this (your path may be different):
(default)  REG_SZ "C:\Program Files\Adobe\Adobe Photoshop Lightroom 4.2\lightroom.exe" "%1"
If this key is missing, you will probably not be able to add Lightroom to Open With.
I actually wonder if Adobe has stopped creating this key for Lightroom 4. When I checked my registry to find the exact key, it still pointed to Lightroom 3.6, even though I have had almost all Lightroom 4 versions installed. And when I tried an Open With, it started Lightroom 3. As soon as I changed the path so it pointed to Lightroom 4.3 RC, Open With started Lightroom 4.